Many presently popular electronic devices are packaged in a plastic molded body with leads formed in a "gull wing" shape. That is, the leads emerge from the body of the device along the edge(s) at the parting line of the molded body. The leads are subsequently formed downward and then outwardly at a point beyond the lower plane of the body. The original intent of this lead form was to allow soldering of the leads in two or four sided devices to a planer circuit board. Leads may emerge from one, two, or four sides of the device. In circuit application which require the device to be removable, a socket is required.
Several sockets have been developed to provide this function. One previous method for applying contact force to the leads has involved a pressure pad which is centrally mounted to a hinged cover. The device is mounted and the cover latched at an edge opposite the hinge, holding the pressure pad so that it applies force to the tops of the outward formed leads of the electronic device. This force depresses resilient contacts which are located under the device leads. The force to operate this system is supplied when the cover is closed. The latch and hinge maintain the force against the depressed contacts. Sockets of this type are typically used in burn-in applications.
Another type of socket has a removable carrier that surrounds the device and provides a surface in direct contact with the top of the outward formed portion of the lead. The carrier, with the retained device, is placed into the body of the socket and pressed until latches can be closed. These latches retain the force of the contacts against the bottom of the leads. This type of socket is primarily used in OEM applications.